5.7 Leafcutter Bee Cocoon Incubation

Leafcutter bees hibernate as larvae inside of their protective leafy cocoons and they need warm temperatures to develop into adult bees, this is called incubation. Leafcutter bee cocoons purchased from Crown Bees are incubated until adult bees begin to emerge.

To incubate your own harvested leafcutter cocoons, plan ahead to time their emergence with your summer weather and open blooms. Place the BeeGuard Bag or CocoonGuard Bag full of harvested cocoons into a dark warm location, like your water heater room. Remember to check periodically for any sneaky pteromalus parasitic wasps and emerged adult bees.

Development is dependent on time spent in warm temperature:

At 84F/30C, adults emerge after about 20 days.

At 70F/21C, adults emerge after about 42 days.

Some native leafcutter bees have shorter development cycles, release these bees as they emerge.

Pteromalus parasitic wasps will emerge after about 9-14 days and will attack developing leafcutter cocoons. Squish them in the incubation bag as they appear.

Pro Tip: To provide leaves for the bees to build their leafy cocoons - plant peas, beans, or strawberries around the same time that you start incubating leafcutter cocoons.

Once adult leafcutter bees start to emerge, you can release cocoons by placing the container of developing bee cocoons into the bee house on top of their 6mm sized nesting holes.